A variety of lighting fixtures have emerged in order to meet people's demands on different kinds of lighting in daily life and at work, and flashlight is widely used due to its lightness and carrying convenience. In general, common flashlights include such major components as cylinder body, lamp cap, luminous element and batteries, and most of them are non-focusable and are nonadjustable in lighting range and brightness, as a result, their lighting range and brightness typically fail to meet the working demand under some situations. Consequently, there are plenty of focus-variable flashlights at present, e.g. Chinese patent CN201210090919.5 entitled Dual Lens Stage Zooming Flashlight, this flashlight comprises an LED light source, a moving lens, a fixed lens, a focusing cover, a cylinder body, a steel ball, a spring and the like; both the fixed lens and the moving lens are arranged in a manner of being perpendicular to an optic axis in front of the LED light source; a constant distance is kept between the fixed lens and the LED light source, and the moving lens is capable of moving back and forth in relation to the LED light source. The lighting area and brightness of exit light can be regulated by changing the distance between the moving lens and the LED light source; in addition, a certain number of fixed holes are arranged on the cylinder body, shallow grooves are arranged among the fixed holes, the steel ball is pressed onto the fixed holes by the spring and can slide from one fixed hole to another along the shallow grooves to achieve stage zooming location. This flashlight, though capable of zooming, has a relatively complex structure; the moving lens is arranged on a moving lens holder, a light transmitting lens also needs to be arranged on the head ring of the lamp cap, and during zooming, movement of the moving lens holder is driven by rotation of the focusing cover, which indispensably leads to arrangement, inside the flashlight, of a hollow cavity used for back-and-forth movement of the moving lens holder, so the flashlight has to be large in length, and becomes non-contractable to further bring difficulty in carrying and storage; meanwhile, the location mechanism is also quite complex, which not only results in troublesome manufacturing and high cost, but is also disadvantageous to maintenance, therefore, further improvement still needs to be applied to its structure.